Floating mine



1944- P. J. M. R..DELALANDE 2,362,192

FLOATING MINE Filed April 28, 1941 grwcwto'a TRIM R elalayae Patented Nov. 7, 1944 FLOATING Paul J. M. R. Delalande, Washington, D- C., as-

signor to United States Ordnance Compan Washington, D. 0., a corporation of Virginia Application April 28, 1941, Serial No. 390,819

14 Claims.

This invention relates to drifting mines, and more particularly to mines for use in rivers, canals or any channels through which a current of water passes for the purpose of destroyin trestles, bridges and the like crossing such stream as the mines are carried along by the current.

One of the objects of the present invention is to provide a simple and practical drifting or floating mine which will be reliable and efficient in use and operation.

A further object is to provide a mine of the above general character which may be conveniently shipped, stored and transported from one place to another and easily and quickly assembled and launched at the bank of the stream.

A further object is to provide a mine of the above character which will float with the major portion just below the surface of the water and. one whose buoyancy may be regulated as desired .to cause the mine to float at a depth where almost invisible.

A further object is to provide a floating mine of the above character which will be perfectly safe to handle prior to its launching and, in fact, up to a few minutes thereafter yet will be extremely dangerous from then on.

A further object is to provide a mine which will function on contact with bridge piers, or pontoons of floating bridges and which will not be easily stopped and prevented from functioning by safety nets or ropes adjacent the pier or pontoon.

A further object is to provide a mine of the first above general character which cannot be easily carried by a swift current between piers or pontoons without contacting one or the other. A further object is to provide a floating mine which may also be used in harbors and carried by the tide. against shipping provided the water is not too turbulent.

A further object is to provide a system .of plural mines exploding together by influence thus spreading the destruction over a wider area and increasing the chances of damaging the superstructure of the bridge as well as its floating or fixed supports.

Other objects will be in part obvious and in part hereinafter pointed out in connection with the following analysis of the invention when taken in connection with the accompanying drawing illustrating one of various possible embodiments of the invention and in which similar reference characters denote corresponding parts throughout the several views. In the drawing- Figure 1 illustrates semi-diagrammatically "a plan view of the complete mine in operative floating position;

Figure 2 is an enlarged sectional elevational view showing one complete part or unit of the mine semi-diagrammatically, together with its means for attaching the same to one of the spars of the complete mine; and

Figure 3 is an enlarged plan View .of the same unit shown in Figure 2.

Referring now to the drawing in detail, and more particularly Figure 1, ,5 indicates a main central part or hub of one complete mine to which is pivotally secured a plurality of radially disposed arms or spars 6, there being four in the present instance. These spars are preferably pivotally connected or detachab'l'y hin ed to .each corner of thehub in any desired manner as by means of conventional hooks and held normally in properly spaced relation by means of flexible and yielding connections such as springs 8 or the like which permit a certain relative swaying movement of the spars with respect to the hub and each other under the action of the waves or current-o when engagin a fixed abu m nt. as may cu unde the circumstances. For

- ample should the center of the mine engage and be held fixed on a pier pr pontoon then the spars w ll tol inwa dly unde th c i n of h current and stret h e p in s until the units ona e the s des of t e -piersand th n e pl de- "By having these members connected as ,derscribed .at the corners of. each of. the hub the spars 16 .on disconnecting. the springs .8 may be folded into substantially parallel relation there.- by to permit more convenient handling, storage or transportation.

At one end .of each spa/r there is provided an explosive charge .of a size suitable to the use of which the mine is to be put. Thus, if the bridge is of a permanent character having stoneupiers, abutment-s or like, it may be desirable to use a relatively'high charge, such as 200 pounds of N. T., or better still a high powered explosive like P. T. suitably boosted; on the other hand}, if the device is intended to destroy small temporary bridges such as pontoon lslridgcs put up by the army engineers over a small river then a smaller charge will answer the purpose.

This mine unit is indicated at 4 0 in-Figure 1, onebeing connected to the outer end of each spa-r 6 which spar may vary in length from ten to twenty feet depending-upon theapproximate or estimated maximum distance between the piers or 'pontoons of the structure to be destroyed.

With reference to Figure '2, itwill be seen that the end of each spar 6 is provided with a boxlike sleeve secured in place by means of pins I2 or the like, and on the underside of this sleeve member is a hinge I3 to which is removably attached one of the mine or explosive charges I0. Thus, this explosive charge may be applied to each spar after the rest of the unit has been assembled and launched,

The mine charge, as shown in the present case, includes a generally cylindrical shaped member ID, the middle part of which carries the explosive It while the lower part I5 constitutes the float chamber adapted to substantially counterbalance the weight of the unit, whereby the unit at the end of the spar is maintained at a distance just below the surface which will just cover the top of the spar 6 of the water. The amount to which it is submerged may be controlled bymeans of one or more removable floats I6 of cork capok (figure) or glass globes on each arm applied as may benecessary to obtain the de sired buoyancy. By having the mine float just below the surface for the :most part renders it difficultto see and almost impossible to hit by rifle fire clue to the tendency of the bullets to recochet. Also it might pass beneath mooring lines connecting pontoons.

' The upper part of the mine'casing I0 carries one or more batteries I1 connected in series one terminal I9 of which is electrically connected to a detonator I8 Within a booster charge in the main mass of explosive I4; The other terminal I9a is connected to the mine casing and circuit closing means about to be described.

The upper part of the mine casing includes a chamber 2I perforated at a plurality of points 22 and containing a hard soluble mass 23. such as a sugar or salt composition adapted to dissolve after a predetermined time interval. Through the central part of this soluble mass passes a rod '24 having at its upper end and positioned at right angles thereto a plurality of feeler arms 25, the outer ends of some of which are provided with grapple hooks 26. The arm parallel to and above the outer end of the spar 6 is coun- Y This vertical rod 24 has terweighted as at 21. an enlarged portion 28 irregular in cross section, square forexample, thereby to prevent any relative rotation of the'aXis of the rod 24 by reason of a correspondingly shaped opening in a gasket 30 through which it passes in water-tight relation. This gasket of rubber or the 'like is clamped in position by means of a ring nut 3| preferably engaging the interior threaded wall of the cylinder 2I in the upper part of the mine casing as shown in Figure 2. Thuswhen the nut 3| is screwed down hard the gasket is locked in water-tight relation with respect to the explosive chamber. r

The rod 24 at its lower end has an insulated pendulum like portion 32 which is normally held in spaced relation from an annular part. 33 of the mine casing by the solid salt or sugar cake and springs 34, yet, when the hooks 26 of the feelers .25, for example, contact a bridge pier, orpon tatable nut 28 in the casing 30 as a center to The above simply describes and illustrates one of various possible contact firing mechanisms and it may be modified in various respects as desired. For instance, it may be preferred to use the disclosure illustrated in U. S. patents to Palmer, 1,471,628, or McKeen, 1,547,510, both of which have proven satisfactory in tests. British Patent, 399,877 shows another modification of a possible firing gear of similar type adapted to fire the mine on contact such as might occur on drifting of the mine into engagement with a bridge, pier, pontoon or ship.

The operation and method of use of the present device is clear from the above description. However, it will be stated that immediately upon determining the nature and size of the bridge to be destroyed, for example, then the desired size of unit is selected and unfolded so as to assume a position substantially such as shown in Figure 1. The various spars or arms 6 are held in yielding but substantially equally spaced position by means of the springs 8. Probably several mines are launched one after the other up stream along the river and immediately thereafter the several mine cases are secured to-the ends of the spars by merely applying a pintle pin to the hinge I3 as shown in Figure 2. Each entire unit, which may be thirty or forty feet in total diameter, is pushed out into the current and the water immediately begins to act upon the soluble mass 23, thereby to release the arm 24 to permit it to move with respect to the non-rotatable connection 28 where contacting with any fixed abutment. Thus, if the drifting'mine first engages a net or guard rope in the current above the bridge the chances are that the grapple hooks 26 at the ends of the unit arms 25 will be tilted either by a push or pull action in such a manner as to close the contacts 32 and 33, thereby to fire that particular unit, thus destroying the net or guard rope adjacent the pier and allowing the following mines to subsequently pass into contact with the structure to be destroyed. If .a pier or a pontoon engages the system right at its center 5, the hinges and springs as arranged will cause the arms 6 to close in and increase the chances of one of the feelers to contact the obstruction. If the spars were rigidly assembled it could happen that the whole system pressed by the current remained in equilibriumagainst the obstacle.

It will be noted that betweenthe top edges of the perforated sleeve 2I and the rod 24 there is provided a plurality of tension springs 34 secured at the outer ends set screws 35 whereby on turning these screws the tension of the spring may be changed thus varyingthe sensitivity of the mine. In relatively rough water such as harbors where the mine might be subjected to swell caused by a passing ship, the springs should be tightened to such an extent that any rocking movement caused by waves or swells from passing craft will not explode the mine.

The present invention is of relatively simple character yet highly reliable and efficient in use and operation. It is safe to handle, easy'to transport, convenient to store and may be quickly se up and used by army engineers.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A floating mine of the character described comprising a plurality of radially disposed rigid spars or the like connected at their inner ends, and an independently actuated contact explosive charge secured directly to the outer end of each rigid spar.

2. The device as set forth in claim 1, including a plurality of radially disposed feelers carried by said explosive charge.

3. The device as set forth in claim 1, including a plurality of radially disposed feelers carried by said explosive charge, grapple hooks on said feelers adapted to engage any obstruction to cause the entire mine to swing about said ob- 'struction or explodetl'ie change so engaged.

4. A floating mine of the character described comprising a central hub, a plurality of rigid spars each secured at one end to said hub, means for holding said spars radially when in operation at substantially equally spaced distances, an independent explosive unit directly supported at the outer end of each spar, and firing means associated with each unit.

.5. The device as set forth in claim 4, in which said firing means includes a plurality of radially disposed feeler arms, firing gear including a detonator, and a circuit adapted to be closed through said detonator when any one of said arms engages a fixed obstruction.

6. A device as set forth in claim 4, in which said firing means includes a pendulum-like member, arms directly connected with said member and a fixed 'contact surrounding said member adapted to be engaged thereby when said feeler arms contact an obstruction.

'7. A floating mine of the character described comprising a central member, a plurality of radially disposed rigid spars connected at their inner ends with said central member, an independent explosive charge including a casing secured directly at the outer end of each of said spars, and means for regulating or controlling the buoyancy of the entire mine.

8. A device as set forth in claim 7, in which said means includes an air chamber in each casing for said independent explosive charges.

9. A device as set forth in claim '7, in which said buoyancy control means includes a plurality of floats secured to said mine.

10. A floating mine of the character described comprising a central body, a plurality of radially disposed and yieldingly connected rigid spars supported at their inner ends from said central body,

"explosive charges, means for directly'securing one of said explosive charges at the outer end of each of said spars, an independently actuating firing means connected with each explosive charge and said securing means comprising connecting means whereby said explosive charge may be easily and quickly applied to or removed from said spars.

11. A device as set forth in claim 10, including means for controlling the buoyancy of the mine.

12. A device as set forth in claim 10, including a safety device operatively connected with each explosive charge.

13. A device as set forth in claim 10 including a safety device operatively connected with each explosive charge adapted to prevent actuation until after the mine has been launched.

14. A device as set forth in claim 10 including firing means for each charge, and a soluble member associated with said firing means adapted to permit operation thereof only after the mine has been submerged a predetermined length of time.

PAUL J. M. R. DELALANDE. 

